Workpiece feeding attachment for a traveling cylinder addressing machine

ABSTRACT

A form feeding attachment for use with addressing machines or the like includes friction rollers for feeding a form from a supply stack to a preprint station, and a conveyor tape for advancing the form from the preprint station to a printing station of the machine where it is held by an automatically operated stop, and then to a receiving hopper. The friction rollers and the conveyor tape are intermittently driven in timed relation with the printing machine such that while a form is being imprinted at the printing station the conveyor tape is inactive and the friction rollers are driven to feed the next form in the stack to the preprint station. On completion of the printing operation, the friction rollers are inactivated and the conveyor tape is driven to advance the form from the printing station to the receiving hopper and the form at the preprint station to the printing station. Means are also provided for detecting the presence or absence of a form at the preprint station and, if the conditions of form presence or absence are not satisfied, the machine is shut down without loss of a printing operation at the printing station. Self-regulating means are provided to adjust the timing of the form stopping and detecting means to accommodate slight differences in the machines to which the attachment is applied. The form stop at the printing station can be adjustably positioned without affecting its drive or timing.

United States tnt' [72] Inventor Robert J. Scranton Mentor, Ohio [21 1Appl. No. 775,342 [22] Filed Nov. 13, 1968 [45] Patented Apr. 13, 1971[73] Assignee Addressograph-Multigraph Corporation Cleveland, Ohio [54]WORKPHECE FEEDING ATTACHMENT FOR A TRAVELING CYLINDER ADDRESSINGMACHllNE 12 Claims, 6 Drawing Figs.

2,561,030 7/1951 Morse 2,608,408 8/1952 Gibson,1r.

ABSTRACT: A form feeding attachment for use with addressing machines orthe like includes friction rollers for feeding a form from a supplystack to a preprint station, and a conveyor tape for advancing the formfrom the preprint station to a printing station of the machine where itis held by an automatically operated stop, and then to a receivinghopper. The friction rollers and the conveyor tape are intermittentlydriven in timed relation with the printing machine such that while aform is being imprinted at the printing station the conveyor tape isinactive and the friction rollers are driven to feed the next form inthe stack to the preprint station. On completion of the printingoperation, the friction rollers are inactivated and the conveyor tape isdriven to advance the form from the printing station to the receivinghopper and the form at the preprint station to the printing station.Means are also provided for detecting the presence or absence of a format the preprint station and, if the conditions of form presence orabsence are not satisfied, the machine is shut down without loss of aprinting operation at the printing station. Self-regulating means areprovided to adjust the timing of the form stopping and detecting meansto accommodate slight differences in the machines to which theattachment is applied. The form stop at the printing station can beadjustably positioned without affecting its drive or timing.

Pat'nted April 13, 1971 3 Sheets-Sheet l JNVE'NTOR BYWGK QR- ATTORNEYPatented April 13, 1971 3,575,108

3 Shoots-Sheet 2 E24 JNVE'NT'OR WM/Qz- AT TOR/VB Y Patented A ril 13,1971 3,575,108

3 Shuts-Sheet: 3

WORKPIECE FEEDING ATTACHMENT FOR A TRAVELING CYLINDER ADDRESSING MACHINEBACKGROUND THE INVENTION The present invention relates to a form feedingdevice and, more specifically, to a form feeding attachment for feedingenvelopes, postal cards and the like to a printing station of anaddressing machine. Conventionally, addressing machines are adapted toimprint forms and documents from embossed printing plates by placing aform overan inked ribbon which overlies the printing plate, and causinga platen to apply printing pressure thereagainst to produce an imprinton the form.

Small volume printing applications generally resort to the use of handoperated addressing machines in which it is necessary to manuallyposition a form to be imprinted at the printing station. Normally, suchmachines are provided with guides or stops against which the form isregistered when it is placed in printing position and, after theimprinting operation is completed, the form is manually removed andreplaced with a new form. While this method of addressing cards andenvelopes provides legible and accurate impressions, it-does not and thelike and, wherein the volume of the work is great enough to justify theadditional cost of such a feeding attachment. j

' Whilethese feeders are reliable in operation and greatly increase theoperating speed, as compared to manual addressing applications, they donot lend themselves "particularl tho.

moderate size applications and especially .to those applications inwhich small size forms such as envelopes and postal cards are being fedand imprinted.

It is an object of the present invention to provide a compact formfeeder adapted to be readily installed as an attachment on existingaddressing machines.

Another object is to provide a form feeding attachment for advancing afour: from a supply stack to a preprint station while a preceding formis beingimprinted, and for feeding the form from the preprint station tothe printing station while the preceding imprinted form is conveyed tothe collection hopper.

. Another object is to provide a fonn feeding device which includessensing means for detecting the'presence or absence of afomi at thepreprint station, and to control machine shutdown if a'forrn is notpresent at the preprint station.

Another object of the invention is to provide a feeder which operates toadvance a form to the preprint station simultaneously with theimprinting of a preceding form at the printing station, and to advancethe form at the preprint station to the printing station simultaneouslywith the conveyance of the imprinted forrn from the printing station tothe receiving hopper.

Another object is to provide a feeding device adapted to feed fomts in astraight path from the front to the rear of an addressing machine intimed relation with the feeding of a printing device from a supplymagazine to the printing station of the machine.

I Still another object is to provide a form feeder which isreliable inoperation, and operable to feed the .forms at a fairly high rate ofspeed, and nevertheless relatively inexpensive to produce.

, Other objects, features and advantages will appear hereinafter as thedescription proceeds.

IN THE DRAWINGS FIG. I is a top plan view of a form feeding-device inaccordance with the practice of the present invention with the top ofthe printing machine shown in phantom lines;

FIG. 2 is a side elevation of the form feeding device of FIG. I mountedon a printing machine with only a fragmentary view in phantom of theprinting machine top and platen mechanism being shown; 4

FIG. 3 is a top plan view in detail of the form feeding device, the viewbeing broken to accommodate it to the page;

FIG. 4 is a section taken substantially on line 4-4 of FIG. 3;

FIG. 5 is a detail plan of the mechanism for actuating and positioning aform stop member drawn to a larger scale;

FIG. 6 is a schematic wiring diagram of a form detection circuit andincludes a diagrammatic showing of the main drive shaft and camsassociated therewith, as they would appear looking from theleft-hand'side in FIG. 3; and

FIG. 7 is a detail'perspective on a reduced scale showing the connectionof a cable drive means from the printing machine to the fonn feedingdevice.

DESCRIPI' ION OF THE PREFERRED EMBODIMENT The feeder device of thepresent invention is adapted to be used, for example, with a printingmachine as disclosed in US. Pat. No. 2,359,850. In such a machine,embossed printing plates are passed sequentially and in a step-by-stepmanner from a supply magazine to a printing station and then to areceiving drawer. I

A roller platen is provided at the printing stationv and isoperated-each machine cycle to produce an impression from a printingplate, through an inked ribbon and onto a form or sheet. During theforward stroke (i. e., the nonprinting stroke) the platen is spaced fromthe form to be imprinted and a form and a printing plate are advanced tothe printing station, and during the rearward stroke (i. e., theprinting stroke) the platen is lowered into pressure engagement with theform overlying the printing plate to image the form. On completion of animprinting operation the platen is again raised to a position spacedfrom the fonn.

As shown in FIGS. 1 and 2, the feeding device is positioned on the tabletop of a printing machine 2, and is secured at the front edge of thetable top by a clamping means 4. The feeding device extends from thefront to the rear of the machine and passes under a printing head 6which carries a platen roller P and a drive lever 8 as best shown inFIG. 2. The lever 8 has a predetermined back and forth oscillatingmotion which could, of course, also be back and forth translation so faras the present invention is concerned, and for the sake of thisdisclosure the term reciprocating will be employed to cover this type ofmotion generally.

The feeding device comprises a supply hopper 10 for retain ing on edge astack of forms F to be imprinted, a feed roller mechanism indicatedgenerally at 12 for advancing a form from the stack to a preprintstation indicated at 14, a conveyor mechanism 16 for advancing a formfrom the preprint station to a work station or printing stationindicated at PS and from there to a deflector 17 which guides the forminto a receiving hopper 18 mounted at the rear of the machine.

As shown in FIGS. 1, 2, 3 and 4, the supply hopper 10 is mounted betweena pair of side plates 20 and 22, and includes a deck plate 24 inclineddownwardly towards the feed roller mechanism 12 for supporting theworkpieces or forms F. A separator blade 26 is mounted on the top faceof the deck plate 24 and is movable towards and away from a series ofseparator rollers 28. The setting of the separator .blade in relation tothe separator rollers is determined by the thickness of the forms beingfed, such that the gap or exit between the front edge of the blade andthe separator rollers permits the passage therethrough of only a singleform at a time. When the blade 26 is properly set it is locked in placeby a thumb screw 30. A formfollower 32 for supporting the rear of thestack of formsis positioned on the separator blade and is adapted tomove by gravity against the stack, and to be manually moved away fromthe stack when forms are being placed in the hopper. The follower 32 isguided in its movement by grooved rollers 34, mounted on the undersideof the follower, which are in rolling engagement with the edges of theseparator blade 26.

The supply hopper is further provided with a pair of side guides 36 and38 for positioning and guiding the forms in the hopper. The side guidesare slidably mounted on a rod 40 fixed in the side plates and 22, andare locked in position on the rod by thumb screws. Additionally, formguides 42 and 44 are slidably mounted on the rod 40 and act against thetop edge of the stack of fonns F to maintain the forms in an uprightposition against follower the follower 32. The form guides are also heldin place on the rod by thumb screws.

The feed rollermechanism 12 comprises the separator rollers 28 mountedon a shaft 48 rotatably joumaled in the side plates 20 and 22 as bestshown in FIG. 3. The separator rollers are preferably made of rubber andare provided with knurled peripheries to provide a positive grippingaction against the first form in the stack to separate it from the restof the stack and advance it to the preprint station 14. The shaft 48 isdriven by a chain 50 which is trained about a sprocket 52 provided onthe shaft 48 and a sprocket 54 provided on a main drive shaft 56. Also,the shaft 48 is provided with a knob 58 to permit manual rotation of theseparator rollers 28 as will be further explained below.

An overload relief device 60 is associated with the separator rollers 28and provides a safety feature to prevent damage to the feed mechanism.In particular, if more than one form at a time tries to become separatedfrom the stack, thereby causing a jam, the added thickness of themultiple forms will tend to hold the separator rollers 28 againstrotation and the overload relief device allows the shaft 48 to continueto rotate.

The feed roller mechanism 12 also includes a pair of pullout rollers 62and 64 mounted on a shaft 66 rotatably supported in the side plates 20and 22. One end of the shaft 66 is provided with a gear 68 in mesh witha gear 70 on the main drive shaft 56 for driving the shaft 66 and thepullout rollers mounted thereon. A pressure roller 72 is positionedbeneath each pullout roller (only one being shown in FIGS. 3 and 4) andprojects through an opening in the deck plate 24 and into engagementwith the pullout rollers. The pressure rollers are supported in brackets76 (only one being shown in FIGS. 3 and 4) and the brackets arepivotally mounted on a rod 80 fixed in the side plates 20 and 22. Thepressure rollers are maintained in engagement with the pullout rollersby springs 82 (only one being shown in FIGS. 3 and 4) which urge thebrackets in a clockwise direction as viewed in FIG. 4. These pressurerollers coacting with the pullout rollers are effective to feed a form Fout of the preprint station 14 when the shaft 66 is driven as will befurther explained below.

The conveyor mechanism 16 comprises a housing providing a sidewall 89and the side plate 22, an endless conveyor tape 90 for transporting afonn from the preprint station to the printing station and,subsequently, to the receiving hopper 18, as shown in FIGS. 1, 2 and 3.The conveyor tape passes around a tape drive drum 92 mounted on a shaft94 supported in the side plates 20 and 22. The shaft 94 is driven by achain 96 which is entrained about a sprocket 98 provided onthe maindrive shaft 56 and a sprocket 100 provided on the shaft 94. From thetape drive drum 92 the lower reach of the conveyor tape extends acrossthe table top of the printing machine 2 and around a roller 102, and thetop reach of the conveyor tape passes over a roller 104, under a seriesof guide rollers 106 and, as shown in FIGS. 3 and 4, under an idlerroller 108 adjacent the tape drive drum. As will be further describedhereinafter, a form being transported is carried at one end by the topreach of the conveyor tape and it is held thereagainst by the series ofrollers 106. The series of guide rollers 106 are carried by a mountingbracket 110 secured to the sidewall 89, and each of the rollers isspring loaded to urge the rollers into engagement with the conveyortape.

Preferably, the bracket supporting the rollers 102 and 104 is madeadjustable so as to permit obtaining proper tension adjustment of theconveyor tape 90.

From the description thus far, it will be seen that the feed rollers 62and 64, the separator rollers 28, and the conveyor tape are all drivendirectly from the main drive shaft 56. The arrangement for driving themain drive shaft willnow be described with reference to FIGS. 2, 3 and7. A drive cable 112 is connected at one end to the reciprocating drivelever 8 and extends rearwardly around a pulley 114. The other end of thedrive cable is connected to one end of a chain 116 which is entrainedaround a sprocket 118 fixed on the main drive shaft 56. The other end ofthe chain is connected to one end of an extension spring 120 and thespring is secured at its other end to a pin 122 provided in a web 124extending between the sidewalls 89 and 22. Thus, as the platen roller Pis driven in a forward stroke in spaced relation above the printingstation, the driver lever 8 pulls the drive cable 112 forwardly (fromleft to right as viewed in these FIGS.) thereby rotating the main driveshaft in an anticlockwise direction against the action of the spring120. On the rearward stroke of the drive lever 8, the platen is loweredinto printing engagement with a form at the printing station and themain drive shaft is rotated in the opposite direction under theinfluence of the spring 120 which maintains the drive cable 112 in ataut condition. Accordingly, the feeder derives its motion directly fromthe motion of the platen mechanism.

The proportions of the above described cable drive are so chosen thatthe motion of the arm 8 is converted to approximately 330 of rotarymotion of the main drive shaft 56 in either direction.

On the forward stroke of the platen the resulting rotation of the maindrive shaft is used to drive the pullout rollers 62 and 64 and theconveyor tape 90 about I I inches. This motion is sufficient to ensurethat all fonns reach the printing station with motion to spare.

Drive to the conveyor tape 90 and the pullout rollers 62 and 64 is takenfrom the main drive shaft 56 by means of a oneway clutch associated withconveyor tape sprocket 100. Thus, on the rearward stroke of the platen,while a form is being imprinted, no drive is imparted to the conveyortape or the pullout rollers.

Drive for the separator rollers 28 is also taken from the main driveshaft 56 by means of a one-way clutch 132 associated with the separatorroller sprocket 52; however, this clutch is oriented to drive on therearward stroke of the platen. Therefore, forms are fed to the printingstation by the pullout rollers and the conveyor tape during the forwardstroke of the platen, and are advanced to the preprint station by theseparator rollers during the rearward stroke of the platen.

One-way clutches (not shown in the drawings) are also provided in eachof the pullout rollers 62 and 64, to permit the rollers to overrun whena form is being advanced to the preprint station by the separatorrollers 28. Also, the one-way clutch 132 of the separator rollerspermits the separator rollers to overrun as a form is being withdrawnfrom the stack by the pullout rollers 62 and 64.

A form stop device indicated generally at is provided to accuratelyposition a form at the printing station. As shown in FIGS. 3 and 5, theform stop device includes a stop member 142 adapted'to be raised andlowered in timed relation with the printing cycle of the machine and,also, adapted to be moved in fore and aft directions to accommodatevarying size forms or varying the location of an impression on the form.

The raising and lowering of the stop 142 is under control of a cam 144provided on the main drive shaft 56. A cam follower 146 is pivotallymounted on a pin 148 provided in the sidewall 22, and extends from thecam to an actuator 150. The actuator is pivotally mounted on a pin 152projecting from a web 151, and is provided with an elongate lip 1S4projecting downwardly towards the printing station. A connecting element156 is pivotally mounted on a pin 153 and includes an ear 1511 at oneend adapted to ride on the lower edge of the lip 154, and at its otherend it is secured to and carries the form stop 142. Thus, when the maindrive shaft is driven in the direction to advance a form from thepreprint station to the printing station, (counterclockwise as viewed inFIG. 4) a depression in the cam surface is presented to the follower sothat the actuator is effective to allow the element 156 to swing aboutthe pivot 153, as a result of the lip 154 retreating from the car 158 ofthe element 156. This movement causes lowering of the stop 142 into thepath of a form carried by the tape to position and hold the form at theprinting station. On completion of the imprinting of the form, the maindrive shaft is rotated in the opposite direction and the stop isrestored to its raised position.

The fore and aft movement of the stop is manually controlled by means ofa rack 160 provided with apertures 162, a pinion 164 meshing with theapertures, and a manually operated rod 166 rotatably supported in thesidewall 22 and web support 166. As best shown in FIG. 5, the rack 160includes a back plate 170 having a pair of elongate slots I71 and 173therein, and a top plate containing the apertures 162 formed at rightangles to the back plate. The rack is slidably mounted on a pair of pins174 and 176 provided in the sidewall 89, such that the pins pass throughthe slots 171 and 173 permitting fore and aft movement of the rackwithin the limits of the slots.

The pinion 164 is fixed to one end of the rod 166 and in engagement withthe apertures 162. A knob 178 is provided at the other end of the rodsuch that by turning the knob the shaft and the pinion are rotated tothereby move the rack 160. However, the rack is also associated with theelement 156 by means of a formed ear 180 which also supports the pivotpin 153 fixed in the back plate 170. Thus, as the rack 160 is movedthrough rotation of the rod 166, its interconnection with the element156 also imparts forward or backward movement to the stop 142 carriedthereby. The ear 158 continues to ride on the lower edge of the elongatelip 154 of the actuator 150 so that regardless of the position of thestop 142, the lip will be effective to act against the ear 158 when theactuator lfifl'is pivoted by the follower 146 and the cam 144.Preferably, the actuator is also provided with a screw 182 and a locknut 164 to adjust the location of the zone of movement imparted to theactuator and, of course, to the form stop 142.

A. detection means is provided and comprises a sensing finger 191)pivotally mounted on a bracket 191 which is fastened to the underside ofthe deck plate 24. As shown in FIG. 4, the sensing finger has an endadapted to coact with a form detector switch S3, and an end 192 whichprojects upwardly through an opening in the deck plate to sense for thepresence or absence of a form at the preprint station.

At this point it should be explained that, since a printing plate is fedto the printing station PS each cycle of the machine, it is necessarythat a form to be imprinted also be advanced to the printing station,i.e., if a form misfeeds and does not reach the printing station, theplaten P will go through a printing stroke without the fonn and theprinting plate will be advanced to the receiving drawer. This, ofcourse, would result in the loss of an impression from that plate andwould require that the plate subsequently be returned to the feedmagazine and again advanced through the printing station.

The detection means avoids loss of a plate at the printing station andis designed to shut down the machine in the event of a form feedfailure. The machine is shut down if the sensing finger 1% does notsense the presence of a form at the preprint station when it is supposedto be there, and it is also shutdown if the sensing finger does notsense the departure of the form from the preprint station at theappropriate time.

With reference to FIGS. 3 and 6, the detection means includes inaddition to the sensing finger 190 and the form detector switch S3, apair of timing switches S1 and S2, under control of cams C1 and C2respectively, mounted on the main drive shaft 56, and a forward andreverse switch FRS controlled by a cam C3 on the main drive shaft.

The cam C3 is frictionally driven by the main drive shaft 56 andcontrolled by a pin 193 so that it swingspromptly to one position or theother to place the switch FRS on a contact representing the direction ofrotation of the shaft 56. In FIG. 6 the upper contact is theanticlockwise contact or forward platen stroke contact, and the lowercontact is the clockwise contact or rearward platen stroke contact(printing stroke contact).

FIG. 6 is in part a diagrammatic view of the cam carrying portion of themain drive shaft 56, and shows the same as viewed in the FIG. 4direction, or as looking from the left in FIG. 3. FIG. 6 is intended toillustrate the parts in approximately the positions which they occupywhen a rearward or printing stroke of the platen P has just beencompleted and a forward or nonprinting stroke is about to begin. This isequivalent to the condition at the commencement of the counterclockwisemotion of the main drive shaft 56. This direction of rotation of themain drive shaft drives the conveyor tape and the pullout rollers 62 and64, during the forward stroke of the platen P, and advances the formfrom the preprint station to the printing station, and the form at theprinting station to the receiving hopper.

As the platen starts to move forward, the cam C3 will shift the switchFRS to the upper contact and hold it there, and the form F will normallybe advanced from the position shown to the printing station, ultimatelyreleasing the sensing finger so that the switch S3 drops to the lowercontact. When the switch S2 is closed by the cam C2 slightly laterduring the cycle, to interrogate switch S3, no circuit will be completedand the printing machine will continue to operate. If, however, the formF failed to leave the preprint station, the interrogation by the switchS2 would complete a circuit through switches S3, S2 and FRS to shut theprinting machine down. It will be understood, of course, that suitableconventional electrical connections (not shown) are provided on theprinting machine for disabling it when the circuit of FIG. 6 iscompleted.

After the platen completes the forward stroke and starts its rearward orprinting stroke, the main drive shaft 56 will start to rotate in aclockwise direction. This rotation of the main drive shaft drives theseparator rollers 28, during the printing stroke of the platen, toseparate a form from the front of the stack and advance it to thepreprint station. This rotation of the shaft also causes the cam C3 toshift the switch FRS to the lower contact. As a form F is fed out of thehopper to the preprint station 14, it will, of course, actuate thesensing finger 191) and shift the switch S3 to its upper contact. At anappropriate subsequent time during the cycle the cam Cl will close theswitch S1 to interrogate the switch S3. In their described positions nocircuit will be completed and the printing machine will continue tooperate. If, however, the form F failed to arrive at the preprintstation when due the interrogation by the switch S1 would complete acircuit through S3, S1 and FRS to shut the printing machine down.

In summary, the switch S3 indicates the presence or absence of a form atthe preprint station, the switch S2, through the switch FRS, checks theswitch S3 for the departure of a form from the preprint station on theforward or nonprinting stroke of the platen, and the switch S1 throughthe switch FRS checks the switch S3 for the arrival of a form at thepreprint station during the rearward or printing stroke of the platen.

Thus, on the forward stroke of the platen only the conveyor tape 90 andthe pullout rollers 62 and 64 are driven, and on the rearward stroke ofthe platen only the separator rollers 28 are driven.

In the event a form is not properly separated from the stack and,therefore, does not reach the preprint station, thus causing shutdown ofthe machine, all that is necessary to restore the machine to operativecondition is to free the hopper jam, if any, and then rotate the shaft48 with the knob 58 in a clockwise direction as viewed in FIG. 4, tothereby advance Similarly, if a form fails to depart the preprintstation as intended causing the machine to shut down, the operatormerely corrects whatever condition caused the malfunction, and manuallyadvances a form to the print position. The form is, of course, removedfrom the sensing finger 190 and the machine can be turned on and itsoperation continued.

The feeder of the present invention is also provided with aself-regulating means for automatically timing the actuation of theinterrogation switches S1 and S2 and the form stop operation in properrelation with the printing machine stroke when the feeder is initiallyinstalled on a machine. This is found to be desirable since there issufficient variance in machine dimensions that there is a noticeablediscrepancy in the location of the feeder hopper in relation to theprinting station and cable attachment point on various machine. Withreference to FIGS. 3 and 6, the means for accomplishing this comprises atiming disc 202 which is drivingly associated with cams S1, S2 and 144,all of which, as a group, are connected to the main drive shaft 56through a slip clutch 200. The timing disc is provided with a projection204 adapted to coact with a stop pin 206 provided in the side plate 22.

Thus, when the feeding device is placed in position on the machine, aform is manually advanced to the preprint station by rotating the shaft48 with the knob 58. When the machine is turned on, the main drive shaftis driven to advance the form to the printing station. As the main driveshaft is rotated, the timing disc is also rotated until the projection204 thereon abuts the stop pin 206. If the timing is not preciselycorrect, the slip clutch 260 is effective to permit the main drive shaftto continue to rotate through the balance of a complete machine cyclewhile the timing disc and its associated cams are held against rotationby the pin 206. This operation requires only one machine cycle toposition the parts in proper timed relation with the printing stroke ofthe machine, and once the timing disc is set it continues to maintain aproper timing relation of the cams until the feeder is shifted toanother printing machine.

When the feeder device is removed from the printing machine it is merelynecessary to unplug an electrical control connection to the mainprinting machine, loosen the clamping means 4, and then to disconnectthe drive cable 112 from the drive lever 8. When the drive cable isdisconnected its free end, which is provided with a hook 210, is securedto a storage pin 212 provided in the sidewall 89, see P10. 3.

However, when the feeder device is again mounted on the machine, itwould be somewhat difficult to grasp the free end of the cable to pullthe same against the action of the rather strong spring 120 in order toconnect the cable to the drive lever 8. Therefore, means have beenprovided for mechanically pulling the cable comprising an arm 214. Asshown in FIG. 3, the arm is pivotally mounted at 216 on a plate 218, andthe plate is fastened to the web 124 and a similar web 220. One end ofthe arm is provided with a pair of projections 222 between which thecable passes, and the cable is provided with a stop enlargement 224fixed thereon to prevent the free end of the cable from passing betweenthe projections and around the pulley 114.

In operation, the arm 214 is moved in an anticlockwise direction asviewed in FIG. 3, thereby causing the projections 222 to act against thestop 224 and withdraw a sufficient length of the cable from the pulleyto connect it to the drive lever. This arrangement affords a mechanicaladvantage which provides for easy withdrawal of the cable from thepulley against the action of the spring 120.

Summarizing the operation of the feeding device, a form is advanced fromthe stack to the preprint station 14 by manually rotating the separatorrollers 28 with the knob 58. The printing machine is now turned on andthe main drive shaft is driven in a direction to cause the pulloutrollers 62 and 64 and the conveyor tape 9-5) to advance the form to theprinting station. At this time the platen is being driven in a forwarddirection and the form stop 142 is lowered, at a time when the trailingedge of a previous form would have cleared the printing station, to stopthe unprinted form when it arrives at the printing station. Since thesensing finger detected the departure of the form from the preprintstation, there is no circuit completed and the machine operation isallowed to continue.

When the forward stroke has been completed, the motion is reversed andthe main drive shaft is rotated in the opposite direction, therebydriving the separator rollers to advance the next form to the preprintstation, and discontinuing the driving of the pullout rollers and theconveyor tape while the platen is printing on the form at the printingstation. Since the sensing finger 190 detected the arrival of the format the preprint station on time, there is no circuit completed and themachine operation is allowed to continue. During the latter portion ofthe stroke the form stop is raised so that the printed form will be freeto progress to the receiving hopper 18 under the influence of theconveyor tape on the succeeding forward stroke.

On completion of the imprinting operation the pullout rollers and theconveyor tape are again driven to deliver the form at the preprintstation to the printing station and the imprinted form to the receivinghopper 18, the form stop lowering at the proper time to detain theincoming unprinted form at the precise printing position.

From the foregoing, it will be seen that the present invention providesa novel feeding device for feeding forms or other sheetlike workpiecesin timed relation with a printing or other work machine operation. Thefeeding device provides for advancing a form to the printing station anda form at the printing station to the receiving hopper during onemachine stroke such as the forward stroke of the platen, and to withdrawthe next form in the stack and deliver it to a ready or preprint stationduring a reverse machine stroke such as the stroke of the platen whilethe form at the printing station is being imprinted. Also, the detectionmeans avoids the loss of a printing plate at the printing station in allinstances wherein the conditions of form presence or absence at thepreprint station are not satisfied. These combined features result in afeeding device which is compact, reliable in operation and relativelyinexpensive to manufacture.

Moreover, there is provided a novel form of transport which is capableof moving a workpiece by one end only with a single tape effectively andefficiently as do transports which use plural tapes. This makes itpossible to provide much greater latitude as to where the impression orwork on the form of workpiece may be placed, in addition to providing amuch less complex and expensive structure.

Since the drive for the demountable feed mechanism is taken directlyfrom an operating element on the printing or primary work machine it ispossible to achieve precise synchronous operation by means of anextremely simple and inexpensive construction.

While the preferred embodiment of the invention has been described andillustrated, it is to be understood that this is capable of variationand modification. Accordingly, the aim in the appended claims is tocover all such variations and modifications as may fall within the truespirit of the invention.

lclaim:

1. An accessory device for feeding sheetlike workpieces to a cyclicallyoperating work machine having a work station, and a moving portion whichis located on the work machine as a permanent part thereof, and iscyclically driven thereby, which comprises:

a frame which is readily attachable to and detachable from the workmachine;

a hopper on the frame for holding a stack of workpieces each having awork area for presentation to the work station for a work operation;

means one the frame for separating a workpiece from the stack and movingit to a ready position;

transport means on the frame for carrying the workpieces from the readyposition past the work station to a discharge point, comprising only onemoving tape leading from the ready position past one side of the workstation and arranged to engage each workpiece at one side thereofoutside the work area thereof, and a plurality of holddown rollers onthe frame urged towards the tape, each so mounted and oriented as toroll only about an axis parallel to the tape surface and substantiallynormal to the direction of tape movement, and spaced closely enoughtogether so that at least two rollers are in engagement with a workpieceat all times until the workpiece is leaving the tape; and

means readily connectable with and disconnectable from the movingportion for driving the separating means and the transport means fromsaid moving portion in timed relation therewith.

2. An accessory device as set forth in claim 11 in which there is alsoprovided:

a stop member on the frame shiftable into and out of an operativeposition for arresting a workpiece at the work station; and

means on the frame associated with said readily connectable anddisconnectable means, to drive said stop member in timed relation withsaid work machine.

3. An accessory device as set forth in claim 2 which further includesmeans to adjust the location of said stop member on said frame so as tooccupy different selected positions with respect to said work stationwithout affecting the stop member drive.

4. An accessory device as set forth in claim 3 in which the locationadjusting means for the stop member comprises a rack and pinion whereinthe rack carries a pivot upon which the stop member is mounted, and thepinion is connected with a manual control knob for operator actuation.

5. An accessory device for feeding sheetlike workpieces to a cyclicallyoperating work machine having a work station and a reciprocating elementwhich is located on the work machine as a permanent part thereof, and iscyclically driven thereby, which comprises:

a frame which is readily attachable to and detachable from the workmachine;

a hopper on the frame for holding a stack of workpieces;

means on the frame for separating a workpiece from the stack and movingit to a ready position;

transport means on the frame for carrying workpieces from the readyposition past the work station to a discharge point; and

mechanism readily connectable with and disconnectable from thereciprocating element for driving the separating means and the transportmeansfrom the reciprocating element when connected thereto, saidmechanism comprising means for driving the separating means in onedirection of movement only of the reciprocating element, and means fordriving the transport means in the other direction of movement only ofthe reciprocating element.

6. An accessory device as set forth in claim Swhich also includes a stopmember shiftable on the frame into and out of operative position forarresting a workpiece at the work station, and in which there is meanson the frame, associated with the readily connectable and disconnectablemeans, for driving the stop member to operative position in the samedirection of motion of the reciprocating element as that which drivesthe transport means.

7. An accessory device as set forth in claim 6 which further includesmeans to adjust the location of said stop member on said frame so as tooccupy different selected positions with respect to the work stationwithout affecting the stop member drive.

8. A device as set forth in claim which further includes detection meansfor stopping the operation of the work machine in case a workpiece isnot transported to the work station comprising:

a sensing finger at the ready position for sensing the presence orabsence of a workpiece thereat;

a first means operable to stop the work machine in response to thesensing finger detecting the presence of a workpIece at the readyposition during the transport operation; and

a second means operable to stop the work machine in response to thesensing finger detecting the absence of a workpiece at the readyposition during the operation of the separating means.

9. An accessory device for mounting on and feeding sheetlike workpiecesto printing machines of a predetermined type, said printing machineseach having a printing station, and having a moving element acting intime with the printing operation, wherein the nature of the printingmachines is such that minor differences can occur in the location of theaccessory device relative to the moving element in mounting theaccessory device on one or another of the printing machines, saidaccessory device comprising:

a frame which is readily attachable to and detachable from the workmachine;

a hopper on the frame for holding a stack of workpieces;

means on the frame for separating a workpiece from the stack and feedingit to and past the printing station;

means on the frame for positively stopping the workpiece at the printingstation during printing and thereafter releasing it to be carried beyondthe printing station to a discharge point;

means for driving the separating means and the feeding means from themoving element including an element readily connectable to anddisconnectable therefrom;

said driving means including a self-regulating means for shifting thetiming of the operation of said stopping means to correct for said minordifferences in the location of the accessory device with respect to themoving element.

10. A device as set forth in claim 9 in which said self-regulating meanscomprises a sleeve member normally drivingly but frictionally associatedwith a shaft on the accessory driven from said proving element, saidsleeve member having an abutment surface, and an abutment in fixedrelation to the axis of said shaft for encountering the abutment surfaceon said sleeve to shift the same to properly timed position; and inwhich the drive means for said stopping means includes a cam operativelyassociated with said sleeve.

ii. A device as set forth in claim 9 in which there is also providedsensing means for determining the location of workpieces at appropriatetimes during the operation and means for arresting the operation of theprinting machine in case a workpiece is not sensed at the appointedtime, and timing means for controlling the operation of said sensing andarresting means, said timing means being also associated with andcontrolled by said self-regulating means.

12. A device as set forth in claim 11 in which said self-regulatingmeans comprises a sleeve member normally drivingly but frictionallyassociated with a shaft on the accessory driven from said reciprocatingmember, said sleeve member having an abutment surface, and an abutmentin fixed relation to the axis of said shaft for encountering theabutment surface on said sleeve to shift the same to properly timedposition; and in which the drive means for said stopping means and thetiming means for said sensing and arresting means include camsoperatively associated with said sleeve.

1. An accessory device for feeding sheetlike workpieces to a cyclically operating work machine having a work station, and a moving portion which is located on the work machine as a permanent part thereof, and is cyclically driven thereby, which comprises: a frame which is readily attachable to and detachable from the work machine; a hopper on the frame for holding a stack of workpieces each having a work area for presentation to the work station for a work operation; means one the frame for separating a workpiece from the stack and moving it to a ready position; transport means on the frame for carrying the workpieces from the ready position past the work station to a discharge point, comprising only one moving tape leading from the ready position past one side of the work station and arranged to engage each workpiece at one side thereof outside the work area thereoF, and a plurality of holddown rollers on the frame urged towards the tape, each so mounted and oriented as to roll only about an axis parallel to the tape surface and substantially normal to the direction of tape movement, and spaced closely enough together so that at least two rollers are in engagement with a workpiece at all times until the workpiece is leaving the tape; and means readily connectable with and disconnectable from the moving portion for driving the separating means and the transport means from said moving portion in timed relation therewith.
 2. An accessory device as set forth in claim 1 in which there is also provided: a stop member on the frame shiftable into and out of an operative position for arresting a workpiece at the work station; and means on the frame associated with said readily connectable and disconnectable means, to drive said stop member in timed relation with said work machine.
 3. An accessory device as set forth in claim 2 which further includes means to adjust the location of said stop member on said frame so as to occupy different selected positions with respect to said work station without affecting the stop member drive.
 4. An accessory device as set forth in claim 3 in which the location adjusting means for the stop member comprises a rack and pinion wherein the rack carries a pivot upon which the stop member is mounted, and the pinion is connected with a manual control knob for operator actuation.
 5. An accessory device for feeding sheetlike workpieces to a cyclically operating work machine having a work station and a reciprocating element which is located on the work machine as a permanent part thereof, and is cyclically driven thereby, which comprises: a frame which is readily attachable to and detachable from the work machine; a hopper on the frame for holding a stack of workpieces; means on the frame for separating a workpiece from the stack and moving it to a ready position; transport means on the frame for carrying workpieces from the ready position past the work station to a discharge point; and mechanism readily connectable with and disconnectable from the reciprocating element for driving the separating means and the transport means from the reciprocating element when connected thereto, said mechanism comprising means for driving the separating means in one direction of movement only of the reciprocating element, and means for driving the transport means in the other direction of movement only of the reciprocating element.
 6. An accessory device as set forth in claim 5 which also includes a stop member shiftable on the frame into and out of operative position for arresting a workpiece at the work station, and in which there is means on the frame, associated with the readily connectable and disconnectable means, for driving the stop member to operative position in the same direction of motion of the reciprocating element as that which drives the transport means.
 7. An accessory device as set forth in claim 6 which further includes means to adjust the location of said stop member on said frame so as to occupy different selected positions with respect to the work station without affecting the stop member drive.
 8. A device as set forth in claim 5 which further includes detection means for stopping the operation of the work machine in case a workpiece is not transported to the work station comprising: a sensing finger at the ready position for sensing the presence or absence of a workpiece thereat; a first means operable to stop the work machine in response to the sensing finger detecting the presence of a workpiece at the ready position during the transport operation; and a second means operable to stop the work machine in response to the sensing finger detecting the absence of a workpiece at the ready position during the operation of the separating means.
 9. An accessory device for mounting on and feeding sheetlike workpieces to printing machInes of a predetermined type, said printing machines each having a printing station, and having a moving element acting in time with the printing operation, wherein the nature of the printing machines is such that minor differences can occur in the location of the accessory device relative to the moving element in mounting the accessory device on one or another of the printing machines, said accessory device comprising: a frame which is readily attachable to and detachable from the work machine; a hopper on the frame for holding a stack of workpieces; means on the frame for separating a workpiece from the stack and feeding it to and past the printing station; means on the frame for positively stopping the workpiece at the printing station during printing and thereafter releasing it to be carried beyond the printing station to a discharge point; means for driving the separating means and the feeding means from the moving element including an element readily connectable to and disconnectable therefrom; said driving means including a self-regulating means for shifting the timing of the operation of said stopping means to correct for said minor differences in the location of the accessory device with respect to the moving element.
 10. A device as set forth in claim 9 in which said self-regulating means comprises a sleeve member normally drivingly but frictionally associated with a shaft on the accessory driven from said proving element, said sleeve member having an abutment surface, and an abutment in fixed relation to the axis of said shaft for encountering the abutment surface on said sleeve to shift the same to properly timed position; and in which the drive means for said stopping means includes a cam operatively associated with said sleeve.
 11. A device as set forth in claim 9 in which there is also provided sensing means for determining the location of workpieces at appropriate times during the operation and means for arresting the operation of the printing machine in case a workpiece is not sensed at the appointed time, and timing means for controlling the operation of said sensing and arresting means, said timing means being also associated with and controlled by said self-regulating means.
 12. A device as set forth in claim 11 in which said self-regulating means comprises a sleeve member normally drivingly but frictionally associated with a shaft on the accessory driven from said reciprocating member, said sleeve member having an abutment surface, and an abutment in fixed relation to the axis of said shaft for encountering the abutment surface on said sleeve to shift the same to properly timed position; and in which the drive means for said stopping means and the timing means for said sensing and arresting means include cams operatively associated with said sleeve. 